NOVA: Deadliest Tornadoes

In April 2011, the worst tornado outbreak in decades left a trail of destruction across the U.S., killing more than 360 people. In this NOVA special, get a look at the science behind the last year’s outbreak, meeting those affected and the scientists striving to understand the forces behind the outbreak.

Debris wrapped around tree in Joplin, Missouri, after the April 2011 tornado outbreak.

Credit: Courtesy of WGBH

A chimney is all that is left here after the April 2011 tornado outbreak - Joplin, Missouri.

AirDat's Bruce Lev and his TAMDAR (Tropospheric Airborne Meteorological Data Reporting) sensor, a mechanism designed to collect highly sophisticated weather data from the atmosphere during the flight of an aircraft.